NO.PZ2018062016000072
问题如下:
For a portfolio including four securities, how many distinct covariance terms are needed to compute the portfolio variance of return?
选项:
A.6
B.12
C.4
解释:
A is correct. For four securities, there are 4*(4-1)/2=6 distinct covariance terms to estimate.
这道题目哪里说需要选2个呢?虽然说了是portfolio,也可以是3只股票呀